4.1

M4.1 Earthquake 229 km ESE of Attu Station, AlaskaJuly 1, 2026

2026-07-01 09:01:29 UTC (3 hours ago) · approx. 9:01 PM UTC+12 local

MagnitudeM4.1(mb)
Time09:01 UTC9:01 PM UTC+12
Depth10.0 kmshallow crustal
Coordinates52.217°, 176.401°
Felt by1DYFI response· max MMI 2.5
Status✓ Reviewed by USGS

On July 1, 2026 at 09:01 UTC, a magnitude 4.1 shallow crustal earthquake struck 229 km ESE of Attu Station, Alaska, at a depth of 10.0 km and coordinates 52.2172°, 176.4008°. The earthquake was reported felt by 1 personacross nearby locations, with a maximum shaking intensity of Modified Mercalli Intensity (MMI) 2.5 (weak).

Physical scale: An earthquake of magnitude 4.1 releases seismic energy equivalent to roughly 21 metric tons of TNT. Empirical fault-scaling laws (Wells & Coppersmith, 1994) estimate the subsurface rupture length at approximately 406 m — a useful intuition for the size of the slip patch on the fault.

Map showing earthquake epicenter at 52.22°, 176.40°

ShakeMap — predicted shaking intensity

Modeled ground-motion intensity contoured on the Modified Mercalli scale (MMI). Computed by the USGS from the moment-tensor solution and regional ground-motion prediction equations.

USGS ShakeMap intensity contours for the M4.1 earthquake near 229 km ESE of Attu Station, Alaska

Source: U.S. Geological Survey ShakeMap. View interactive ShakeMap on USGS

Did You Feel It? — community-reported shaking

Aggregated felt-report intensity from 1 citizen response to the USGS Did You Feel It? system. Each colored zone represents the average MMI from reports in that area.

USGS DYFI community-reported intensity map for the M4.1 earthquake near 229 km ESE of Attu Station, Alaska

Source: U.S. Geological Survey Did You Feel It?. View on USGS · submit your own report

Earthquake Details

Magnitude
4.1 mb
Depth
10.0 km
shallow crustal
Location
52.2172°N
176.4008°E
Felt Reports
1
DYFI responses
Intensity (MMI)
2.5
weak
Community Intensity
2.0
CDI from reports

Technical Information

Event ID
us6000t9dl
Event Type
earthquake
Status
✓ Reviewed
Significance
259
Stations Used
68
Azimuthal Gap
149.0°
Min Station Distance
1.365°
RMS Residual
0.63 sec
Last Updated
2026-07-01 09:45:40 UTC

Common Questions

How strong was the magnitude 4.1 earthquake near Attu Station, Alaska?

The magnitude 4.1 earthquake that struck 229 km ESE of Attu Station, Alaska on July 1, 2026 at 09:01 UTC had a depth of 10.0 km. It was felt by 1 person with maximum shaking intensity of MMI 2.5 (weak). For context, this was a light earthquake commonly felt near the epicenter.

Were there aftershocks?

Aftershock activity is monitored continuously by the USGS. Aftershock sequences from magnitude 4.1 earthquakes can continue for several days and gradually diminish over time.

What should I do after an earthquake?

If you were in the affected area: check yourself and others for injuries, inspect your home for damage, and be prepared for aftershocks. For detailed guidance, see our earthquake safety guide and emergency planning resources.

Authoritative source: USGS event page (event ID: us6000t9dl). All scientific values on this page are sourced verbatim from the USGS feed.

Cite this page: EarthquakeTracker.org. (2026, July 1, 2026). M4.1 Earthquake 229 km ESE of Attu Station, AlaskaJuly 1, 2026. Retrieved July 1, 2026 from https://www.earthquaketracker.org/earthquakes/event/us6000t9dl/